This invention relates to fastening and unfastening an apparatus to a threaded bolt. More particularly, but not by way of limitation, this invention relates to a slip-nut apparatus and method of using the slip-nut about a threaded bolt.
In the industrial applications, pumps are used on a regular and frequent basis. The types of industrial pumps include, but are not limited to, triplex pumps, centrifuge pumps, etc. During the course of pump use, operators will find it necessary to pull valve seats. The reason for pulling out the valve seats will vary, as will be understood by those of ordinary skill in the art. For instance, the valve seat may become damaged, clogged, corroded, etc. Therefore, the valve seat may need to be repaired and/or replaced.
Regardless of the specific reason for pulling the valve seat, the operation has proved to be time consuming. In normal operation, a puller stem with attached valve seat puller is inserted into a passageway in the pump. The puller plate will abut the pump case. A wrench is threadedly disposed about the puller stem and is adjacent the puller plate. The puller stem is rotated which in turn advances the valve seat puller into engagement with the valve seat. The valve seat can then be pulled.
Additionally, the operator will then pull the second valve seat. The wrench will be backed-off by rotating the wrench thereby allowing the wrench to advanced via the threads to the desired length of the second valve seat. The advancement is accomplished by the rotational engagement of the thread means of the wrench and puller stem as is understood by those of ordinary skill in the art.
A major disadvantage of the prior art puller stems is that the threaded shaft may contain nicks, cuts, corrosion and/or other damage. Thus, in the advancement of the wrench about the puller stem, a great amount of time is consumed. As will be understood by those of ordinary skill in the art, operators want to minimize the amount of time that the pumps are out of service. Thus, the amount of time for advancing the wrench is a significant problem in the terms of productivity. Also, when the puller stem contains damaged threads, the task can be physically challenging for the operator.
Therefore, there is a need for a slip-nut that can be used in conjunction with a threaded shaft. There is also a need for an apparatus that will make it easier for operators to change valve seats from pumps. There is also a need for a method for changing valve seats in a more efficient and economical fashion.